| abstract |
The cavitation-resistant polyurethane composition comprises a first solution and a second solution. The first solution is prepared by a polymerization reaction of 60 to 70% by weight of isocyanate having 2 or more average functional groups and 30 to 40% by weight of a polyol having two average functional groups, and a urethane prepolymer containing an isocyanate functional group . Wherein the second solution comprises from 90 to 95% by weight of a polyol having an average number of functional groups of 4 or more, from 1 to 3% by weight of nano-carbon, from 1 to 3% by weight of a colorant, from 1 to 3% by weight of a hygroscopic agent, And 1 to 3% by weight of an antifoaming agent. Wherein the molar ratio of the functional group (NCO) of the isocyanate of the urethane prepolymer to the functional group (OH) of the polyol having 4 or more average functional groups is 1.0: 1.0 To 1.05: 1.0. As a result, it has flexibility and rigidity and is excellent in chemical resistance, water resistance, durability, adhesive force, abrasion resistance, impact resistance, cavitation resistance, and spraying work, which can shorten the working time in forming a coating film. |